Perpustakaan Digital ITB

Gasification is considered as an alternative method coal utilization to produce hydrogen as an energy carrier. However, it also produces greenhouse gases that harm the environment. Thus, biomass is added to coal in a co-gasification process in order to achieve high content of hydrogen but low greenhouse gases due to their alkali and alkaline earth metals (AAEM) content. However, with the use of biomass, tar production is high due to the high volatile matter contained in biomass. Catalytic gasification with CaO optimizes hydrogen in syngas production with a low concentration of tar by absorbing CO2 and cracking tar. This research uses lignite coal as gasification feedstock, clamshell as the catalyst, and seaweed as co-feedstock which has self-catalytic activity due to its high content of AAEM. The coals were prepared by removing minerals that inhibit gasification performance with demineralization using HF. While the clamshell was calcined in a furnace at 900oC. The gasification process lasted for 50 minutes. Syngas produced was analyzed using gas chromatography (GC) for its composition and char produced was analyzed by comparing the yield. The effect of seaweed addition to demineralized and raw coal gasification were observed respectively, and the effect of CaO catalyst to demineralized coal gasification was also discerned. AAEM presence in seaweed is proved to be promoting hydrogen production in demineralized coal-seaweed variations by 2.2 times than raw coal-seaweed gasification results and 10.7 times more hydrogen than demineralized coal gasification, but it showed a negative synergy effect in raw coal-seaweed variations. Silica content in coal had a great impact towards raw coal-seaweed gasification performance with hydrogen production of 0.62 of the coal gasification results. While CaO presence in calcined clamshells gave better gasification performance in producing hydrogen by 3.8 times compared to AAEM in demineralized coal-seaweed variations.